void changePriority(int priority)
{ /*change priority of an item in the heap */
   int position, newPriority, parent, child;
   element item;
   position = searchHeap(priority);
   if (!(position)) {
        printf("%d is not in the priority queue.\n", priority);
		return;
	}
	printf("New Priority: ");
	scanf("%d", &newPriority);
    item.key = newPriority;
	if (item.key > heap[position/2].key)
	{/* new priority is higher than current priority */
	   while (1)	
	      if ((position == 1) || (item.key <= heap[position / 2].key))
	         /* terminate when the root is reached or the element
	         is in its correct place */
		break;
	   else {
	      /* check the next lower level of the heap */
	       heap[position] = heap[position/2];
	        position /= 2;
		}
        heap[position] = item;
     }
	 else {/* new priority is lower, so go down the heap */
	   parent=position;
       child=position *2;
       while (child<=n) {
	     if (child= heap[child].key)
	           /*correct position has been found */
	           break;
	         else {
	            /* move to the next lower level */
	            heap[parent] = heap[child];
	             parent = child;
	             child *= 2;
			}
		}
		heap[parent] = item;
	}
}